1. Field of the Invention
The present invention relates to a structure of a writing utensil, and more especially to an automatic adjustment and control structure for writing liquid which enlarges the capability of storage, strengthens the ability of anti-leakage and improves the utility.
2. Description of the Prior Art
Currently there are certain drawbacks in traditional writing utensils, such as leakage, unsmooth writing, poor capability and short useful life. Additionally the writing liquid often has not been substantially utilized. However, all of these have brought users so much inconvenience. By research people discover that the key factor resulting in the drawbacks above-mentioned is ill structure of writing utensils. These drawbacks could not be overcome unless the structure has been improved.
Present writing utensils throughout the world including fountain pens, ball pens, roller pens, markers, and so on have three main types on the basis of structure, though their variety and function are quite different.
One type is a filter structure used widely which depends on a roll-shaped fibrous means to absorb, store and supply the writing liquid. However, it has stored finite writing liquid and has poor utilization ratio that is only about 60 percent, which results in short useful life. In addition, when writing since the writing liquid reduced gradually the writing liquid has been pulled by a force directed from the writing tip, while it has also been absorbed by a force caused by the roll-shaped fibrous means. The two forces are converse so as to induce unsmooth writing. Moreover, it is prone to leak when the roll-shaped fibrous means is full of writing liquid.
Another type is a storage structure usually applied on fountain pens. This structure adopts a special sheet-shaped storage to control the supply of writing liquid and prevent from leakage. Unfortunately, the whole structure is very complicated and requires to be molded integrally. The design, manufacture, craft and precision thereof are substantially technical. Additionally, the channels for air and writing liquid are both tiny and single, so once any one of them has been blocked, the use of the whole writing utensil will be influenced unavoidably. Its shape and capability would be restricted for its function and posture.
Still another type is by utilizing a “floating lid”, which belongs to the field of ball pens. The “float lid” is liquid which controls flow of air and the writing liquid. This structure has poor capability because it has been technically restricted by the diameter of the storage hole. The flow of writing liquid is easily affected by shake and temperature. At present this structure is only used in ball pens and gel pens.
These years some new structures have occurred, such as “spring valve”, “glove valve” and a combination of a filter structure and a storage. But some of them have uneven flow of writing liquid during use and then it often requires pressing the writing tip, so these writing utensils can not write continuously. During the air pressure changed or the ambient temperature rose, causing the air within the writing utensils to expand, since the valves do not have function of self-adjustment, when pressing the writing tip again, writing liquid is easily to burst forth. The convey line of other structures is the common single channel for both air and writing liquid, upon that the flow out of writing liquid and the inflation of air are performed in a same channel but from converse directions, which has effect on the pass in and out of air and writing liquid. Moreover, the outlet of the convey line is located below the capillary storage, so the overflowed writing liquid by air expansion reaches the bottom of the capillary storage first and then in stock, thereby affecting the capability and air exhaust of the capillary storage. If the air within the writing utensil expands again, its practical function would be dropped off remarkably.
Although structures of writing utensils are improved to a certain extent, some so-called new structures are more complicated rather than overcome the known drawbacks, but also bring a lot of new trouble. These new structures are not accepted and recognized by people seems that improvement of structures is not easy and simple.
Generally, the present structures of writing utensils could not escape from the former pattern. The drawbacks deriving from ill structures come down historically, but the research and development to structures are really lagged, especially at the times that the society and science advance rapidly.